Prince Harry celebrated the latest round of his royal-trashing tour by downing tequila shots with Stephen Colbert — who mercilessly mocked him while teasing their interview before it airs late Tuesday.

The 38-year-old exiled royal was seen getting served the shots with salt and lime Monday while taping his chat for “The Late Show” in the Ed Sullivan Theater in Manhattan.

Harry — whose memoir, “Spare,” details his heavy drinking and drug taking — was photographed grinning as the 58-year-old host served up the drinks.

Studio guests told the Daily Mail that Harry downed the shots after taking part in a quiz where he answered silly questions such as his favorite sandwich and phone app.

Photos also showed armed guards carefully covering the prince, who has been accused of putting his life at risk by bragging about killing 25 Taliban troops while on active service with the UK military.

Colbert teased the interview on his show that night — then immediately mocked his upcoming guest, saying that “Spare” was “also available on audiobook and a commemorative plate.”

“I’ve read the book – it’s very enjoyable, quite emotional, quite revealing. I’m going to have so much to talk about with his Harryness,” he quipped of the much-leaked tome that officially went on sale Tuesday.

He then dismissed one of Harry’s many complaints about his brother, heir Prince William — about him wanting him to ignore him at school — as being “straight out of the older brother/sibling playbook.”

“Well that’s heartbreaking,” Colbert said with mock angst after playing a clip of Harry saying how “hurt” he’d been by the decades-old slight that he took “personally.”

“I mean, to be rejected by his older brother at school even though that magic hat sorted them into the same house,” Colbert joked, pretending the royal brothers were part of “Harry Potter.”

“What do you think? Hufflepuff? Hufflepuff? Gryffindor, I’m not sure,” he quipped, naming houses from the J.K. Rowling series.

Colbert then joked about Harry’s “crisp description” of his older brother’s “scowl” and “alarming baldness” — and his claim that it wasn’t “cutting at all.”

Smirking, Colbert quipped: “No — cos William’s so bald he doesn’t need any cutting, am I right? Am I right Harry?”

The host then held up his hand for a high-five from Harry — quipping: “Don’t leave me in the Tower of London up here.”

“Tune in tomorrow to find out if he leaves me hanging,” Colbert told his viewers.

Colbert also joked about the royals as a whole — including the late Queen Elizabeth II — by saying: “Stock up on corgis and steal a priceless cultural treasure from one of your colonies because The Late Show is going imperial.”